Internal Engine Prob or no??

OK, so had the prob of car not wanting to start after days of sitting about a week after headwork/cam/headers/injectors. Car eventually started after numerous tries and threw EGR Ricurculation code, got fixed. Now went to start it about 3 days later, and nothing again, turns over, fuel pump turns on, and i know hear something resembling a loose peice of metal(bolt) in the driver side head, seems to be jumping around when starting up? ANy ideas?

I'd pull that valve cover before I tried starting it again.